Microsoft has published Virtual Private Networking with Windows Server 2003: Deploying Site-to-Site VPNs
Describes how to deploy a PPTP-based or L2TP/IPsec-based site-to-site VPN connection, configuring firewalls for a VPN router running Windows Server 2003, alternate configurations, and troubleshooting.Virtual Private Networking with Windows Server 2003: Deploying Site-to-Site VPNs
